Methods and apparatus for detachably assembling the barrel of a firearm

ABSTRACT

A firearm includes a slit receiver socket for detachably receiving a barrel, and a spacer element disposed between the rear of the barrel and the end of the socket to define the rearmost position of the barrel. The spacer element may include a plurality of discs which are adhered together. Discs may be added to or removed from the spacer element to adjust the size thereof.

United States Patent 1191 Bielteldt, deceased et al.

[ Sept. 10,1974

1 1 METHODS AND APPARATUS FOR DETACHABLY ASSEMBLING THE BARREL OF A FIREARM [75] Inventors: Heinz Bielfeldt, deceased, late of Eckernforde, Germany; by Gerlinde Bielteldt; by Karsten Bielfeldt, both of Eckernforde; by Christiane Diehl, Kiel. all of Germany. heirs [73] Assignee: J. P. Sauer & Sohn GmbH,

Eckernforde, Germany [22] Filed: Apr. 26, 1973 [21] App]. No.: 354,773

[30] Foreign Application Priority Data July 21, 1972 Germany 2236001 [52] US. Cl. 42/75 B, 42/1 Q [51] Int. Cl. F416 21/00 [58] Field of Search 42/75 B, 1 Q, 76 R, 77; 89/14 R, 16

[56] References Cited UNITED STATES PATENTS 761,463 5/1904 Fay 42/75 B 1,393,057 10/1921 Vollmer 3,731,418 5/1973 Birkenhagen .1: 42/75 B Primary ExaminerBenjamin A. Borchelt Assistant Examiner-C. T. Jordan Attorney, Agent, or Firm-Burns, Doane, Swecker & Mathis 5 7] ABSTRACT A firearm includes a slit receiver socket for detachably receiving a barrel, and a spacer element disposed between the rear of the barrel and the end of the socket to define the rearmost position of the barrel. The spacer element may include a plurality of discs which are adhered together. Discs may be added to or removed from the spacer element to adjust the size thereof.

9 Claims, 1 Drawing Figure PATENTEDSEP 10 I974 METHODS AND APPARATUS FOR DETACHABLY ASSEMBLING THE BARREL OF A FIREARM BACKGROUND AND OBJECTS OF THE INVENTION The invention relates to a firearm, preferably a handheld firearm, with a replaceable barrel, which barrel has its rear end detachably inserted into a corresponding 'recess of the receiver head. The rearrnost position of the barrel is defined by an axial stop. The receiver head or socket has a longitudinal slit in its underside facing the shaft or socket and is arranged in a reinforced manner as an abutment or support. Clamping elements are provided which releasably clamp together the opposing sides of the abutment which face each other along the longitudinal slit, in general accordance with related U.S. Birkenhagen patent application, Ser. No. 126,441 filed on Mar. 22, 1971, now US. Pat. No. 3,731,418.

This type of construction, as expressed in the related application, has the advantage that the barrel of the weapon or firearm can easily and quickly be replaced without the requirement of a subsequent refinishing or reworking to zero-in in the firearm, accordingly whereby no special tools are needed. Since, however, the determination of the distance between the end of the barrel and the breech is accomplished by a locally fixed edge on the receiver, against which edge the barrel, with a flange, is pulled, a subsequent adjustment of the distance of the barrel relative to the breech is no longer possible.

It is the general object of the invention to remedy this situation.

It is a principal object of the invention to provide a novel firearm combination affording the replacement of barrels without the need for special stop edges on the barrel which must be of close tolerance.

It is yet another object of the invention to provide such a combination wherein the distance between the breech mechanism and the rear end of the barrel can be conveniently and effectively adjusted.

BRIEF SUMMARY OF THE PREFERRED EMBODIMENT In achieving at least some of these objectives, the preferred embodiment of the invention involves the insertion of at least one spacer element between the end of the barrel and the base of the recess in the head of the receiver, into which the end of the barrel is inserted. This spacer then constitutes the axial stop.

The barrel therefore is inserted into the recess in the head or socket of the receiver to such a point until it abuts firmly against the spacer and is then clamped down firmly by the clamping arrangement for further use. At the same time, there is the possibility to regulate exactly the desired distance of the end of the barrel from the breech by a suitable selection of thickness and number of spacers.

The preferred spacers employed are those which are built up from a multiplicity of very thin individual shims, preferably discs, which are held together by some adhesive.

In the production of the weapon in this manner, one can proceed considerably more economically, insofar as it will be possible to permit considerable production tolerances in the case of the use of a laminated spacer of 1 mm thickness. Thus, the barrel, the receiver, and

the chamber bolt or breech elements can be made according to the points of view of modern serial production. The adjustment of the breech distance in each case is accomplished solely by insertion of the spacer, the thickness of which is largely variable by pulling off or adding on individual layers of shims.

It has furthermore turned out to be of advantage to provide both the end of the barrel and the recess in the head of the receiver, as known per se, with a corresponding thread. In this fashion, after insertion of the spacer, or of several spacers, into the recess, the barrel first of all is screwed sturdily against the spacer and the head of the receiver is clamped down by the clamping elements for fixing the barrel in place.

THE DRAWING Other objects and advantages of the invention will become apparent with reference to the following detailed description of a preferred embodiment thereof in connection with the accompanying drawing, wherein like reference numerals have been applied to like elements and in which:

The only FIGURE in the drawing shows a longitudinal section through a firearm at the rear end of the barrel, in accordance with the invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION The barrel, designated by 10, has a rear end portion 11. The rear end 11 is slightly thinner in its diameter than the front of the barrel and is provided with an abutment or support 14, developed slightly reinforced, in front of the receiver socket or head 13 seated on the receiver breech casing 12. This abutment 14 has a longitudinal slit indicated in the drawing and is penetrated transversely by clamping elements 15. In the receiver, the breech bolt 16 can be recognized with the firing pin 17 mounted in it. The remaining elements do not need to be specially designated in this connection, as they are conventional.

The embodiment shown by way of example has a threaded connection 18 between the receiver head 13 and the rear end 11 of the barrel 10. Thus, the barrel, with its clamping element 15 relaxed, can be separated, without the aid of special tools, by screwing from the receiver head.

To this point, the firearm has been described in accordance with the basic principles of US. Birkenhagen Pat. Application Ser. No. 126,441, filed Mar. 22, 1971, now US. Pat. No. 3,731,418, and assigned to the assignee of this invention. The disclosure of this Birkenhagen application is incorporated herein by reference.

In order to produce now the required distance between the breech of the firearm and the rear end of the barrel, a spacer element 19 is inserted at the base of the recess in the receiver head 13. Subsequently, the barrel is screwed in by means of the thread 18 into the receiver head 13 to such a point until it rests firmly on or against the spacer element 19. The spacer element 19 comprises one or more shims preferably in the form of discs, the number and thickness thereof depending upon the size of the distance required between the breech mechanism and the end of the barrel. If a plurality of discs are employed, they are preferably detachably glued together. The discs include aligned central apertures to permit passage of a cartridge therethrough.

To deploy a difierent sized spacer element, a new spacer element may be substituted. Alternatively, discs may be selectively added to or peeled from the spacer element already in use.

SUMMARY OF MAJOR ADVANTAGES AND SCOPE OF THE INVENTION With this invention, a precise adjustment of the required distance between the breech mechanism and the barrel end is possible without there being any need for a stop edge always being present immediately on the barrel, which edge is subject to production tolerances and runs against or abuts a collar at the head of the receiver. The mounting is as simple as possible and the storage of the spacers is not expensive. Moreover, the spacer element can be conveniently adjusted for various barrels.

Although the invention has been described in connection with a preferred embodiment thereof, it will be appreciated by those skilled in the art that additions, modifications, substitutions and deletions not specifically described may be made without departing from the spirit and scope of the invention as defined in the appended claims.

What is claimed is:

1. In a firearm having a barrel and receiver means; the receiver means including socket means for detachably receiving a rear end portion of a barrel, support means disposed generally beneath said socket means, longitudinal slit means formed in said support means to permit contraction of said socket means, and releasable clamping means for inducing convergence of opposite sides of the slit means to contract said socket means; and axial stop means for defining the rearmost axial position of said barrel; said axial stop means comprising spacer means inserted between an end portion of said barrel and the base of said socket means.

2. A firearm according to claim 1 wherein said socket means and the end of said barrel include corresponding thread means.

3. A firearm according to claim 1 wherein said spacer means comprises a plurality of discs adhesively secured together and disposed between the end walls of said barrel and said socket means.

4. A firearm according to claim 3 wherein said socket means and the end of said barrel include corresponding thread means.

5. A firearm according to claim 3 wherein said discs include aligned central apertures therethrough.

6. A firearm according to claim 1 wherein said spacer means comprises at least one shim, said shim including a central aperture therethrough.

7. A method of adjustably assembling a barrel within a receiver socket of a firearm, said method comprising the steps of:

providing a spacer element;

inserting said spacer element within said receiver socket;

inserting said barrel within said receiver socket such that a portion of said barrel abuts said spacer element; and

securing said barrel within said socket.

8. The method according to claim 7 wherein said step of providing a spacer element includes the step of adhering together a plurality of shims.

9. The method according to claim 7 wherein the step of providing a spacer element comprises the step of detaching at least some of a plurality of adhering shims which define said spacer element. 

1. In a firearm having a barrel and receiver means; the receiver means including socket means for detachably receiving a rear end portion of a barrel, support means disposed generally beneath said socket means, longitudinal slit means formed in said support means to permit contraction of said socket means, and releasable clamping means for inducing convergence of opposite sides of the slit means to contract said socket means; and axial stop means for defining the rearmost axial position of said barrel; said axial stop means comprising spacer means inserted between an end portion of said barrel and the base of said socket means.
 2. A firearm according to claim 1 wherein said socket means and the end of said barrel include corresponding thread means.
 3. A firearm according to claim 1 wherein said spacer means comprises a plurality of discs adhesively secured together and disposed between the end walls of said barrel and said socket means.
 4. A firearm according to claim 3 wherein said socket means and the end of said barrel include corresponding thread means.
 5. A firearm according to claim 3 wherein said discs include aligned central apertures therethrough.
 6. A firearm according to claim 1 wherein said spacer means comprises at least one shim, said shim including a central aperture therethrough.
 7. A method of adjustably assembling a barrel within a receiver socket of a firearm, said method comprising the steps of: providing a spacer element; inserting said spacer element within said receiver socket; inserting said barrel within said receiver socket such that a portion of said barrel abuts said spacer element; and securing said barrel within said socket.
 8. The method according to claim 7 wherein said step of providing a spacer element includes the step of adhering together a plurality of shims.
 9. The method according to claim 7 wherein the step of providing a spacer element comprises the step of detaching at least some of a plurality of adhering shims which define said spacer element. 